Preschool-age children that present attention-deficit/hyperactivity disorder (ADHD), non-compliance, aggression, and defiance are especially at risk for serious social, educational, and psychiatric adjustment difficulties throughout the development. However, very few studies have examined the efficacy of a parent training program for children with these characteristics, and none have been done so with Latino children (PCIT), a family based parent training treatment, for Puerto Rican children aged 4 to 6 years with a diagnosis of ADHD who also present high rates of conduct problem behaviors. The initial efficacy, feasibility, and acceptability of the culturally adapted PCIT will then be evaluated by a randomized controlled pilot study. The participants in this pilot study will be 80 clinic-referred children with a DSM IV diagnosis of ADHD hyperactive-impulsive type or combined typed. These children will be randomly assigned to the PCIT program (n=40) or a minimal contact waiting list condition (n=40). Each participant and their parents will receive pretreatment and posttreatment testing. The design will be a 2 (treatment) x2 (times of assessment) with repeated measures on the last factor. The two groups will be compared on measures of observed parent- child interactions, parent and teacher behavior rating scales, and parent self-report questionnaires. A 3.5 month follow-up testing will be done for the participants in the treatment condition.